Controlling system



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CQNTROLLIHG SYSTEI Filed lay 21, 1941 FLIGHT ENGINEERS I CONTROL :1

.motors may be pitch adjusting Patented Oct. 27, 1942 CONTROLLING SYSTEMWilliam F. Fell, Trenton, N. 3., assignor to Bendix South Bend, Ind, acor Aviation Corporation, poration of Delaware Application May .231,1341, Serial No; 394,555

. 1 Claim.

This invention relates to speed controlling systems, and moreparticularly to a means for controlling the speed of aircraft engines.

It is an object of the present invention to provide a system formulti-engined aircraft, whereby the speed of any one or more engines maybe separately controlled, but wherein all engines are subject tosimultaneous and uniform control.

It is another object of the invention to provide a system whereby theindividual control of the propeller or throttle of any engine of amultl-engined aircraft may be effected under certain conditions, butunder other conditions, all engines may be subject to simultaneouscontrol. 1

Other objects will appear from a study of the following specificationwhen made in conjunction with the attached drawing.

The single figure of the drawing is a schematic diagram of an electricalcircuit representing an embodiment of the present invention.

The system represented in the drawing will accommodate the simultaneousor individual adjustment of the propeller or throttle of each engine ofa four-engine craft. A central master control station it, has afour-armed switch mem ber ll, centrally pivoted adjacent a circularterminal board l2, having four sets of contacts, each set of which hascontacts marked l, 0 and ii. A battery l3, having one side grounded at64, is connected by means of a conductor I5, to the central portion ofswitch member I l. Four sets of conductors l6, l1, l8 and i9, each sethaving three conductors, extend between the master pilots station I0,and a secondary control station 20. This station has four switchmembers, 2|, 22, 23 and 24, each capable of deilection from the opencircuit condition, as shown, to one or the other of the contacts markedl and 2. These contacts in each set are connected to the terminalsmarked 1 and 2, respectively, of each set of terminals at the masterstation ill. Each of the series wound motors 25, 26, 21 and 28, has oneof the field members 29, 30, 3| and 32, connected to terminals I andswitch assemblies 2|, 22,23 and 24, and oppositely wound fields 33, 34,and 36, connected to their respective terminals 2. The motors havearmature members, 31, 38, 39 and 40, carrying, respectively, shafts 4|,42, 43 and 44. Each has one side of its armature connected to ground at45 through conductors 43, 41, 48 and 49. These motors of the typedesignated at 3 in the patent of Tumbull, 1,793,653, (Variable pitchpropeller),

or they may (ill. 172 239) be connected to the throttle valve of each ofthe four engines oi the aircraft.

With switch it having its four arms on the 0 contacts of the terminalboard i2, the knife switches, 2i, 22, 23 and 24 are at batterypotential, and as the armatures 37, 38, 39 and 4B of these motors are incircuit with battery l3 by way of the ground connection 45, uponmovementof any or all of switch members 2i, 22, 23 or 24 to either of theterminals l or 2 at the secondary station 23, the motors 25, 23, 27 and28, or any of them, may be energized and cause the propeller or thethrottle setting of the engines to be varied. If we assume that shafts4!, 42, 43, M will be rotated clockwise upon the closing of switches El,22, 23, 24, respectively, upon their individual terminals i, thenrotation of shafts 4i, 2, 43, M, will be counterclockwise upon theclosing of the switches 2 3, 24 upon their respective terminals 2, asthe oppositcly wound fields 29, 3d, 36, 3a, and 33, 3t, 35, 38, willcause armatures 32 38, 39, it to rotate in opposite directions.

It has been proved to be quite necessary in the operation of large boatsto be able to make individual adjustment to each engine propeller inflight, and this control is edected by the flight engineer at stationtil. Whil it is important that the prop-chars be individually adjustedat certain intervals in flight, there are other times, particularlyduring takeoff and landing, at all engine and propeller adjustmeats canbe made with safety only under control of the pilot or captain.

When the arms of switch it are moved to the position indicated by thedotted lines, all the propellers will be turned in one direction, forexample, in a direction to increase the pitch. until the desired pitchindication or engine speed has been obtained, after which, the pilot mayreturn switch ii to the position shown. With the switch arms of switchll marked 2, battery potential is removed from the switch blades 2|, 22,23 and 24, so that the flight engineer cannot possibly make anindividual adjustment to the propeller of any of the engines. Likewise,when switch H has its arms in the position indicated by the dash lines,all the propeller motors are simultaneously operated to vary thepropeller pitch in the opposite direction, for example, to decrease thepitch. With arms of switch it in this position, switch blades 2|, 22, 23and 24 are disconnected from the battery I3, and the flight engineercannot possibly make an adjustment of the pitch of any all on thecontacts propeller while the pilot is adjusting all propellerssimultaneously. When the arms of switch II are returned to the positionshown in the drawing, on the 0 contact, the propellers will maintain theadjustment given them by the pilot until such time as the flightengineer decides to individually adjust any of the propellers of theaircraft. I

Thus, it will be appreciated that the pilot or flight captain may exertfull control over the throttle or pitch varying units without having tosignal to any other station for such control, and yet, when the flightengineer wishes to make routine propeller or throttle adjustments, heknows that these adjustments cannot be made I contrary to the wishes ofthe flight captain, as

be understood that various changes may be made without departing fromthe scope of the present invention. For this reason, it is intended notto limit the invention by the description herein given as an example,but solely by the scope of the appended claim.

What is claimed is: v An engine speed adjusting system, comprising aplurality of speed controlling motors, a master speed controllingcircuit, a secondary speed controlling circuit, means in said secondarycircuit to selectively control the operation of one or more of saidmotors, means in said master circuit for exerting simultaneous controlof all of said motors, and means controlled by said master circuit forpreventing independent control of any of said motors by said secondarycircuit during simultaneous operation of said motors under the controlof said master circuit.

F. FELL.

